Tool for cleaning and/or drying a cavity

ABSTRACT

The invention relates to a tool for cleaning and/or drying a cavity in a workpiece, such as a hole, in particular a threaded bore. The workpiece has a workpiece adapter. The workpiece adapter includes a workpiece contact surface and has a connector for feeding cleaning medium and/or drying medium. There is an opening in the connection adapter for discharging cleaning medium and/or drying medium containing dirt particles. A nozzle having a nozzle chamber is formed in the workpiece adapter. The connector opens into the nozzle chamber such that a cyclonic flow of the fed cleaning medium and/or drying medium can form in the nozzle and exits the nozzle. The cyclonic flow transports dirt particles from the cavity in the workpiece to the opening for discharging dirt particles and cleaning medium and/or drying medium.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the national stage application of internationalpatent application PCT/EP 2011/052937, filed Feb. 28, 2011, designatingthe United States and claiming priority from German application 10 2010002 633.6, filed Mar. 5, 2010, and the entire content of bothapplications is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a tool for cleaning and/or drying a cavityaccessible through an opening, for instance a recess in a workpiece, forexample, a bore, in particular a threaded bore, comprising a workpieceadapter which has a workpiece contact surface and a connection for thesupply of cleaning medium and/or drying medium and which has an openingfor the discharge of dirt particles and cleaning medium and/or dryingmedium containing liquid or vapor particles. The invention also relatesto a cleaning and/or drying apparatus comprising such a tool. Inaddition, the invention relates to a process for cleaning and/or dryingrecesses, in particular bores and threaded bores, in workpieces.

BACKGROUND OF THE INVENTION

A tool and a process of the type mentioned in the introduction are knownfrom DE 103 18 238 B4. The document describes a tool for cleaning theinner surfaces of threaded bores in a workpiece which has a lance-shapedblowing insert. This blowing insert can be inserted into a threadedbore. A supply channel for cleaning medium is formed in the blowinginsert. The supply channel has an opening slot which extends in thelongitudinal direction over the blowing insert. The opening slot servesfor directly applying a flow of cleaning medium tangentially to the wallof a threaded bore. Dirt particles can thereby be removed from thethread turns in the threaded bore. In order to achieve a satisfactorycleaning action with this cleaning tool, it is necessary to adapt thelength of the blowing insert to the depth of a threaded bore to becleaned. The cleaning tool therefore has a technically complex design. Arotatory movement of the cleaning tool is additionally required for thedefined cleaning of portions of a threaded bore which lie far away fromthe opening slot in a workpiece.

For machining workpieces, for instance engine components, for example,cylinder heads, cooling lubricants are used and chips are formed. As aresult, workpieces are contaminated. These contaminants can causedisruptions in subsequent installation processes and impair thetechnical functionality of systems which are produced from correspondingworkpieces. Instances of contamination with cooling lubricants and chipsin cylinder head bores and injection nozzles can cause irreparabledamage to the engine in the case of internal combustion engines.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a tool having an improvedcleaning and/or drying action for recesses in a workpiece, and also tospecify an improved process for cleaning and/or drying workpiecerecesses which is suitable, in particular, for removing coolinglubricants and chips from bores, in particular from blind bores and fromthreaded bores, and for cleaning and/or drying cylindrical cavitieswhich are open on one side.

This object is achieved by a tool of the type mentioned in theintroduction, in which a nozzle with a nozzle chamber is formed in theworkpiece adapter, into which nozzle chamber the connection for thesupply of cleaning and/or drying medium opens in such a manner that acyclonic flow of cleaning and/or drying medium supplied into the nozzlecan form in the nozzle, the cyclonic flow transporting dirt particlesfrom the recess in the workpiece to the opening for the discharge ofdirt particles and cleaning medium and/or drying medium containingliquid droplets or vapor in the workpiece adapter.

One concept of the invention is that the wall of a recess in a workpiececan be cleaned and/or dried with a high degree of efficiency by applyinga cyclonic flow thereto, like the wall of a hydrocyclone which is usedfor the centrifugal separation of liquid mixtures. In addition, oneconcept of the invention is to use the so-called secondary cyclonicflow, which is in the form of the inner, usually upwardly directedvortex in a hydrocyclone, for transporting away dirt particles or liquiddroplets out of a recess in a workpiece.

The tool can be operated with fluids as the cleaning medium, inparticular with air, gas or water. A high cleaning action can beachieved by operating the cleaning tool with cleaning medium which ismixed with granules or ice crystals. The tool can also be used fordrying cavities. To this end, hot air is economically used as the dryingmedium in the tool.

In a preferred configuration of the invention, the nozzle chamberextends with a tapering cross-sectional geometry toward the workpiececontact surface. A particularly good cleaning action and/or dryingaction is achieved in that the nozzle chamber has an annular gap openingin a portion on the workpiece side. In particular, it is advantageous ifan outflow channel is formed in the nozzle chamber, with which outflowchannel dirt particles and cleaning medium can be transported to theopening in the tool adapter. In this case, it is practical if theoutflow channel has an axis which is aligned with the nozzle axis. Sincethe outflow channel has a displaceable inlet opening for dirt particles,the removal of dirt particles from the recess in the workpiece can beoptimized. It is advantageous in particular if the inlet opening of theoutflow channel for dirt particles, liquid particles or liquid vapor canbe moved into the recess in the workpiece. In an advantageousconfiguration of the invention, the workpiece contact surface is formedwith a sealing portion, which preferably comprises a seal, for example,an O-ring, and with which the recess in the workpiece can beencompassed.

The tool according to the invention is suitable for use in an apparatusfor cleaning and/or drying, which comprises a device for the supply ofcleaning and/or drying medium, which provides pressurized cleaningand/or drying medium through a fluid channel for the tool. In this case,it is possible to simultaneously clean and/or dry a plurality ofworkpieces having recesses or a plurality of recesses on a workpiece inthat the apparatus for cleaning and/or drying comprises a multiplicityof corresponding tools. In particular, it is practical to provide asingle-axis or else multiple-axis manipulator, in particular a handlingrobot, for the apparatus for receiving workpieces having recesses whichare to be cleaned or dried, by means of which manipulator a receivedworkpiece can be placed onto the workpiece contact surface of a tool.

The invention also consists in cleaning a recess in a workpiece, forexample, a bore, in particular a threaded bore or else a cylindricalcavity, for instance the interior of a tube with a termination, byguiding cleaning medium and/or drying medium into the recess in theworkpiece with a primary cyclonic flow. A liquid fluid or else a gaseousfluid can be used here as the cleaning medium. In particular, it ispossible in this case to transport away particles out of the recess bymeans of a secondary cyclonic flow which forms in the recess. Hot air,for example, is suitable for drying a recess in a workpiece. Aparticularly good cleaning effect can be achieved if the primarycyclonic flow is generated by way of a nozzle formed in a workpieceadapter which lies against the workpiece. Here, it is practical if theworkpiece adapter encompasses the recess in the workpiece with a sealingaction by way of a sealing portion formed in a workpiece contactsurface. With this cleaning process, in particular bores or threadedbores can be cleaned with the outlet opening of the nozzle being adaptedto the bore diameter of the bores or threaded bores by means of whichoutlet opening the primary cyclonic flow is generated. In addition, boreholes in walls, in concrete or rock can also be cleaned using a toolaccording to the invention. Air or water is particularly suitable as thecleaning medium for this purpose. Since, here, the cleaning medium whichis mixed with dirt particles, for instance air and concrete dust, andwhich flows through the opening for the discharge of dirt particles andcleaning medium in the workpiece is guided through a filter system or iscollected by way of a filter bag, it is possible to avoid contaminationof the environment with, in particular, dust-like dirt particles.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the drawingswherein:

FIG. 1 shows a section of a tool for cleaning and/or drying with aworkpiece;

FIG. 2 shows a section of the tool for cleaning and/or drying in theplane II-II from FIG. 1;

FIG. 3 shows a plan view of the tool for cleaning and/or drying in theplane from FIG. 1;

FIG. 4 shows a cleaning apparatus comprising a plurality of tools forcleaning and a manipulating robot; and,

FIG. 5 shows a section of a tool for cleaning and drying tubular bodieswith a termination.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 shows a tool 1 for cleaning and/or drying on a workpiece 2. Thetool 1 comprises a workpiece adapter 3. The workpiece adapter 3 has aworkpiece contact surface 5 and comprises a nozzle 7 with a nozzlechamber 9. The nozzle chamber 9 extends along an axis 11 in a mannerrotationally symmetrical to an opening 13 in the workpiece contactsurface 5. In a portion 14 which faces toward the workpiece contactsurface 5, the nozzle chamber 9 is conically tapered, that is, thediameter of the cross section of the nozzle chamber 9 decreases towardthe workpiece contact surface 5.

The tool 1 has a connection 15 for a cleaning or drying medium. FIG. 2shows a section of the tool for cleaning in the plane II-II of FIG. 1.The connection 15 is guided through the housing of the nozzle chamberoffset laterally in relation to the axis 11 of the nozzle chamber 9. Theconnection 15 opens by way of an opening 16 in the side wall 17 in thenozzle chamber 9. In this case, the wall portion 22 of the connection 15merges tangentially into the wall 17 of the nozzle chamber. This has theeffect that the fluid flow 43 at the connection 15 in the nozzle chamberis forced to circulate, such that the desired primary cyclonic flow 37is formed in the nozzle chamber 9. Pressurized cleaning or drying mediumcan flow through the connection 15 into the nozzle chamber 9. An outflowtube 19 projects into the nozzle chamber 9. The outflow tube 19 forms anoutflow channel 20 for cleaning medium which is mixed with dirtparticles 6, or for drying medium which is mixed with liquid and/orvapor particles.

FIG. 3 shows a plan view of the workpiece contact surface 5 of theworkpiece adapter 3. The end portion 23 is provided with an opening 24,through which cleaning fluid, which is mixed with dirt particles orcorresponding drying medium, can flow into the outflow tube 19. The wall(25, 27) of the outflow tube 19, which lies in the region of theworkpiece contact surface 5, delimits an annular gap 29 with the wall 17of the nozzle chamber 9 on the workpiece contact surface 5.

An outer diameter of the outflow tube 19, which is three times greaterthan the width of the annular gap 29, is practical. Tests have shownthat a very good cleaning action or drying medium can be achieved withthe tool 1 when the length of the nozzle chamber 9 is approximately 8times the diameter with which the connection 15 for cleaning mediumopens into the nozzle chamber 9.

The outflow tube 19 is arranged so as to be adjustable in the nozzlechamber 9 according to the double-headed arrow 21. The outflow tube 19has an end portion 23 on the workpiece side. By moving the outflow tube19 according to the double-headed arrow 21, the positioning of theopening 24 thereof can be initiated. The opening 24 can be positionedwithin the nozzle chamber 9. However, it is also practical for theoutflow tube 19 to be set in such a way that the opening 24 is locatedin the plane of the workpiece contact surface. It is also advantageousthat it is possible to set the outflow tube 19 in a position in whichthe opening 24 is arranged within a recess 4 in the workpiece 2.

A particularly good cleaning or drying action can be achieved with thetool 1 particularly in the case of workpiece bores with a diameter 30which corresponds to the diameter of the opening 13 in the nozzlechamber 9 in the workpiece contact surface 5.

The recess 4 in the workpiece 2 has a threaded bore 4. Dirt particles 6are present in the threaded bore 4. The threaded bore 4 is a blind holehaving a tapering geometry at the bottom region 12. In order to cleanthe threaded bore 4 of the dirt particles 6, the workpiece 2 with thethreaded bore 4 is placed onto the workpiece contact surface 5 of theworkpiece adapter 3 in such a way that the axis 8 of the threaded bore 4is aligned with the axis 11 of the nozzle chamber 9 in the tool 1. Inorder to make it possible for the workpiece contact surface 5 to bearsealingly against the workpiece 2, the tool contact surface 5 has asealing portion 31 with a seal in the form of an O-ring 33.

For cleaning the threaded bore 4, pressurized cleaning medium 35 for theconnection 15 on the tool 1 flows laterally into the nozzle chamber 9.In the process, a primary cyclonic flow 37, by way of which the cleaningmedium passes into the threaded bore 4 of the workpiece 2, forms in thenozzle chamber 9.

In the threaded bore 4, the primary cyclonic flow 37 entrains the dirtparticles which are trapped in thread paths 10. On account of theconically tapering geometry in the portion 14 of the nozzle chamber 9,cleaning medium is displaced in the direction of the axis 11 of thenozzle chamber 9. This leads to a build-up in the threaded bore 4. As aresult, a secondary cyclonic flow 39, which transports dirt particlesfrom the threaded bore 4 toward the tool 1, is formed in the borehole12. This secondary cyclonic flow 39 is accepted by the outflow channel20 of the outflow tube 19. It passes via the outlet opening 41 in theoutflow tube 19, together with the dirt particles 6, to the outside.

FIG. 4 shows a cleaning apparatus 50 comprising a plurality of cleaningtools (52, 54, 56, 58). Each cleaning tool (52, 54, 56, 58) has astructure which corresponds to that of the tool 1 in FIGS. 1 and 2. Thecleaning tools (52, 54, 56, 58) are accommodated on a cleaning block 60.On the cleaning block 60, the cleaning tools (52, 54, 56, 58) aresupplied with cleaning medium via pressure connections (62, 64, 66, 68).This cleaning medium is conveyed from a fluid tank 71 via a pump block70. The cleaning block 60 is provided with an outflow channel 72 forcarrying away cleaning medium mixed with dirt particles to a collectiontank 74. As an alternative to this, the cleaning medium mixed with dirtparticles can also be guided to a processing system for cleaning medium,for example.

The cleaning apparatus 50 comprises a handling robot 76, with which aworkpiece in the form of an engine block 78 can be arranged on thecleaning tools (52, 54, 56, 58) in a pinpoint manner, in order to cleandirt particles from threaded bores (80, 82, 84, 86) in the engine block78.

As an alternative to this, it is also possible to provide asingle-jointed or multi-jointed manipulator for the cleaning tools (52,54, 56, 58), with which manipulator the cleaning tools can be movedtoward a corresponding workpiece.

The tool 90 in FIG. 5 is designed for cleaning and drying a tubular body92 which has a cylindrical hollow volume 93 by means of hot air. To thisend, the tool 90 has a workpiece adapter 94 having a nozzle chamber 96.The through-opening 97 in the nozzle chamber 96 has a diameter whichcorresponds to the inner diameter of the tubular body 92. The tool 90has an outflow tube 96, which serves as a discharge for hot air mixedwith dirt particles and liquid particles. The outflow tube 96 is adaptedto the length of the tubular body 92. By injecting pressurized hot air98 through the connection 100 of the tool 90 via the opening 108 in thenozzle chamber 96, which, like the opening 16 in the nozzle chamber 9 ofthe tool 1 shown in FIG. 1, is offset laterally in relation to the axis106 of the nozzle chamber 96, a primary cyclonic flow 102 forms in thenozzle chamber 96 and in the tubular body 92. The cyclonic flow entrainsdirt particles and liquid droplets on the inner wall of the tubular body92. A secondary cyclonic flow 104 is formed in the region of the lowertermination of the tubular body 92. This cyclonic flow 104 is collectedby way of the outflow tube 96, and thus passes to the outside.

To summarize, the following preferred features are noted: a tool 1 forcleaning and/or drying a recess 4 in a workpiece, for example, a bore,in particular a threaded bore, has a workpiece adapter 3. This workpieceadapter has a workpiece contact surface 5 and has a connection 15 forthe supply of cleaning and/or drying medium. There is an opening 41 inthe workpiece adapter 3 for the discharge of cleaning and/or dryingmedium mixed with dirt particles. A nozzle 7 with a nozzle chamber 9 isformed in the workpiece adapter 3. The connection 15 for the supply ofcleaning and/or drying medium opens into the nozzle chamber 9 in such amanner that a cyclonic flow 37 of cleaning and/or drying medium can formin the nozzle 7, the cyclonic flow exiting the nozzle 7. The cyclonicflow 37 transports dirt particles 6 from the recess 4 in the workpiece 2to the opening 41 for the discharge of dirt particles 6 in the workpieceadapter 3.

The invention claimed is:
 1. A worktool for cleaning and/or drying arecess in a workpiece wherein dirt particles and/or vapor particles canaccumulate, the worktool comprising: an adaptor having a workpiececontact surface for contacting said workpiece when cleaning and/ordrying said recess thereof; said adaptor including a housing and anozzle having a nozzle chamber formed in said housing; said housinghaving a side wall delimiting said nozzle chamber and said nozzledefining an axis; a connection for passing a medium for cleaning and/ordrying said recess into said nozzle chamber; said connection beingguided through said side wall with an offset with respect to said axisso as to open in a wall section of said side wall passing tangentiallyinto said side wall of said nozzle chamber; said adapter having anopening through which said medium with said dirt particles and/or saidvapor particles exit therefrom after said medium has passed into andfrom said recess; an outflow channel arranged in said nozzle chamber fortransporting said medium with said dirt particles and/or said vaporparticles to said opening; and, said outflow channel defining an axis inalignment with said axis of said nozzle.
 2. The worktool of claim 1,wherein said nozzle chamber extends toward said workpiece contactsurface with a tapering cross-sectional geometry.
 3. The worktool ofclaim 1, wherein said nozzle chamber has an annular-shaped gap formed ina section thereof facing toward said workpiece.
 4. The worktool of claim1, wherein said outflow channel has a displaceable inlet opening forreceiving said medium with said dirt particles and/or said vaporparticles.
 5. The worktool of claim 4, wherein said inlet opening ofsaid outflow channel is displaceable into said recess of said workpiece.6. The worktool of claim 1, wherein said workpiece contact surface has asealing section causing said recess in said workpiece to be effectivelysealed in surrounding relationship thereto.
 7. The worktool of claim 6,wherein said sealing section includes a seal.
 8. The worktool of claim1, wherein said recess in said workpiece is accessible via an openingformed therein and said medium is a cleaning liquid or drying air or hotair.
 9. The worktool of claim 1, wherein said recess is a threaded boreformed in said workpiece.